Sizing and desizing of regenerated cellulose textile materials



Patented Mar. 5, ,1940

/ SIZING AND DESIZING 0F REGENERATED CELLULOSE TEXTILE MATERIALS Herman S. Bosland, Paterson, N. J., assignor to Stein, Hall & Company, Inc.-, New York, N. Y., a corporation of New York No Drawing. Application June 14, 1937, Serial No. 148,112

10 Claims.

This invention relates to the treatment of fibrous materials, more particularly textile materials made from regenerated cellulose, and to improvements in sizing and desizing such materials.

The use of starch and starch derivatives for the sizing of textile materials, with particular reference to warp sizing, has long been known and'in use. The use of starch products is simple and economical, and certain types of starch derivatives are particularly suitable for the warp sizing of regenerated cellulose fibers, such as rayon, etc. One object of my invention has particular reference to the desizing of regenerated cellulose.

Notwithstanding the ease and economy in the use of certain starch derivatives for the sizing of regenerated cellulose, it has been found difiicult, particularly on certain types of weaves, to remove or desize the starchy coating from the fabric after it has been woven. In many cases the use of enzymes under controlled conditions is called for, and such. conditions in the desizing or rinsing of the fabric have curtailed the use of starch derivatives.

One object of my invention is to improve these rinsing or desizing properties in a starch derivative sizing product, so that after mild and simple washing treatment, the starchy matter is readily removed. A further object is to obtain new and improved results in the sizing of regenerated cellulose textile materials. Other objects will ap pear hereinafter.

These objects are accomplished through the incorporation in the dry amylaceous sizing material of a substantial amount of carbamide commonly known-as urea. Although the latter is a well-known substance and has been used in combination' with starch for certain purposes. such as veneer glue, it has not heretofore been applied to starchy sizing mixtures in the treatment of regenerated cellulose for the purpose of aiding in the subsequent removal of starch in the final desizing of the fabric. The nature of the mechanism of this action probably arises from the afllnity of urea for water, thereby drawing the water into the fabric and aiding in the loosening of the starchy coating.

The invention will be further illustrated but is not limited by the following example in which the quantities are stated in parts by Weight:

Example I A regenerated cellulose yarn made by the viscose process was sized by passing it into a bath containing an intimate dispersion of 10 parts of a modified starch prepared by one of the usual methods of treating starch, 1.5 to 3 parts of urea, and to 300 parts of water. Prior to the introduction of the regenerated cellulose material the above mixture was heated and agitated at a temperature of 180 F. for 15 minutes. The yarn'was sized at a temperature of 135 to F. by the usual method of skein sizing. However, the-sizing bath may be hot or cold. This formula can also be used in warp sizing. If desired, the sizing composition may be made up by heating the designated portions of starch and urea with a smaller amount of water, say 60 parts of water, and then diluting.

The resultant regenerated cellulosic material was then woven in the usual manner and the size readily removed by washing with water. Very satisfactory results were obtained.

In a similar manner other compositions may be prepared in accordance with the invention with varying proportions of urea and. amylaceous matter, The term amylaceous substance" is herein employed tocover starches and starch degeneration products including dextrins. In practicing the invention it is usually preferable to employ a starch degeneration product, by which is meant a derivative of-starch such as may be obtained by the various processes of making thin-boiling and so-called soluble starches and dextrins. By a specially modifiedstarch is meant a starch degeneration product which; after having been colloidally dispersed in water, yields a dried protective film of suitable physical characteristics for the purpose involved. In order to obtain these characteristics and to form'so-called solutions suitable for textile application, ordinary undegenerated starch is suitably degenerated in part, or modified, by various chemicals and heat treatments. If desired, mixtures of undegenerated starch and modified starches may be used in conjunction with the urea.

Among suitable starchy materials may be mentioned whea't, rye,'barley, oat, rice, maize and potato starches, sago and cassava flours and collodial modifications thereof and other starches and flours and derivatives thereof.

The ratio of solids to water in sizing compositions for regenerated cellulose is preferably within the range of about 1:9 to about 1:30.

The amount of urea will naturally be determined somewhat by the amount of water, because the maximum amount of urea will normally be less than the amount required for saturation under ordinary temperature and pressure conditions.

ine; ample, sulfonated oils,

( e. g., dodecyl sulfate, cetyl sulfate, and similar The method of treatment may be the warp method, skein method or any other suitable method. Ordinarily the bath may be either hot or cold. The amount of sizing composition retained by the materials treated will depend largely upon the concentration of the bath and the time of treatment. Good results are obtained by applying to the regenerated cellulose yarn a relatively small amount of sizing composition as, for instance, about 4% to about 6% by weight of the material. Ordinarily, in this treatment it is pref erable to employ a composition containing a major proportion of binding agent and a minor proportion of urea.

It will be recognized that a wide variety of auxiliary agents may be added to the sizing compositions herein described, although excellent results are obtained without the addition of any auxiliary agents. Among such addition agents may be mentioned fullers earth, bentonite, wetpenetrating and dispersing agents, f0r exhigher alcohol sulfates compounds), diethylene glycol, glycerine and related substances. The proportions of these materials may also vary, depending upon the type of treatment and the material treated. For instance, it is usually preferable to use about one part of glycerine, or two parts of Turkey red oil, for each 80 parts of sizing composition in the treatment of regenerated cellulosic materials. It will be observed, however, that thecompositions herein,described are permanently water dispersible and contain no ingredients which would tend to render them insoluble under the-influence of heat or upon drying.

In preparing the sizing composition it is preferable to prepare a dry blend of amylaceous material and urea as a base material. This blend is marketed in dry or powdered form and requires only the addition of water and mixin preferably with heating, to produce the sizing composition.

Auxiliary materials may also be included in the dry base.

The regenerated cellulose may be prepared in any suitable manner, for example, by the viscose, nitration or cuprammonium'methods.

It will be apparent that the invention is very 4 advantageous in providing a method for sizing fibers to withstand the friction and regenerated cellulose textile materials prior to weaving, while at the same time insuring ready removal of the sizing material after weavin without resorting to expensive and dimcult procedures. While the primary object of the present invention is to size regenerated cellulose materlals with amylaceous compositions in a man: ner such that the sizing composition may be readily removed after weaving merely by washing or rinsing with water, it may be observed that the presence of urea in the composition does not destroy but rather improves the action oi the composition in temporarily strengthening the mechanical action of the loom. Another advantage in employing urea lies in the fact that the base composition is non-liquid and may be readily handled. Likewise the ingredients may be readily mixed in the proper proportions requiring only the addition of water to produce the sizing composition.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In the art of sizing cellulose materials, the step which comprises applying to the material a permanently water dispersible composition containing an amylaceous substance and urea.

2. A method of sizing regenerated cellulose yarn which comprises treating it with a permanently water dispersible intimate dispersion of an amylaceous substance and urea in water, the amount ot'urea. being less than the amount of amylaceous substance and the ratio of solids to water being within the range of 1:9 to 1:30.

3. A method of sizing regenerated cellulose yarn which comprises treating it with a permanently water dispersible intimate dispersion of about 10 parts of a modified starch and about 1.5

to 3 parts of urea in about 120 to about 300 parts of water.

4. A regenerated cellulose sizing composition comprising an intimate dispersion 01' a permaand desizing regenerated nently water dispersible amylaceous substance,

and urea in water. v

5. A regenerated cell ose sizing composition comprising a, permanently water dispersible intimate dispersion of a starch" degeneration product and urea in water, the amountof urea being less than the amount of starchdegeneration product and the ratio of solids to water being within the range of 1:9 to 1:30. j

6. A sizing composition adapted for sizing regenerated cellulose fibers. prior to weaving and consisting essentially of an intimate dispersion of about 10 parts oi a modified starch and about 1.5 to about 3 parts of urea in about 120 to about 300 parts of water.

' 7. A regenerated cellulose material sized with a permanently water dispersible intimate dispersion of an amylaceous substance and urea in water.

8. A regenerated cellulose material containing a permanently water dispersible sizing composition consisting essentially of a major proportion of an amylaceous substance and a minor proportion of urea.

9. A method of sizing regenerated cellulose yarn prior to weaving which consists in treating it with a permanently water dispersible sizing composition having an amylaceous material as substantially its sole binding constituent, said composition containing urea in an amount substantially less than the amount of amylaceous substance.

10. A regenerated cellulose material sized with a permanently water dispersible composition having an amylaceous material as its sole or substantially its sole binding constituent, said composition containing urea in an amount substantial less by weight than the amount of amylaceous material.

HERMAN S. BOSLAND. 

